Info needed: 67 M38A1 CDN 2 Backfire

[Les Kovacs]

Started jeep up after two weeks vacation....+30C temp in garage...crank but no start after 3-4 seconds (unusually starts first crank)....tried a second time-crank but no start after 2-3 seconds.....then I put on the choked thinking that fuel may have evaporated from carb....cranked then backfired once and then it started. Why the backfire.

Thanks in advance,

les

[Mike Kelly]

Originally Posted by Les Kovacs

Started jeep up after two weeks vacation....+30C temp in garage...crank but no start after 3-4 seconds (unusually starts first crank)....tried a second time-crank but no start after 2-3 seconds.....then I put on the choked thinking that fuel may have evaporated from carb....cranked then backfired once and then it started. Why the backfire.

Thanks in advance,

les

A guess. There might have been unburnt fuel in the exhaust manifold , the fuel ignited and then a bang .

[rob love]

For a Jeep to start consistently on the first crank is not usual. They are not electric fuel pumps. I would suggest you have a carb that's leaking fuel slightly, thus priming the engine while it sits. Two weeks worth of sitting overprimed it, resulting in a slightly flooded condition. The choke would not have made that better.

Your car at home, with it's electric fuel pump and computerized engine system has the capabilities of having the right mix of fuel at the intake based on the temps and conditions....your old Jeep does not.

[Les Kovacs]

Thanks Rob....since that backfire start.....the jeeps is starting well again everyday. Any idea where the carb would be leaking and what do I look for.....for a fix?

I would also like to replace the cap, rotor, points & condenser...is this something a novice can do and how do I make sure its timed right.

Thanks,

les

[rob love]

A novice"Could" replace those parts, but a novice can also f-up those parts while doing it. Really, unless there is something wrong, leave them alone. And when the vehicle does start to give trouble starting, just replace the points and condenser unless something else stands out as problematic. Caps are fairly expensive, and some of the surplus ones (tagged with mil-quip as the supplier on the boxes) don't even fit right, requiring the holes to be bored oversize to work properly.

Changing the points and properly setting them will not likely require a timing adjustment. But if you do want to set your timing, remove the number one wire at the spark plug, and install about a 5" piece of regular 7mm wire to the end. Put the flush end back into the spark plug, and you can test the timing with an inductive timing light and hooking the light to one battery only.

Hard to say where the fuel could be leaking down from. One item I commonly see on the jeeps is that the 3 large screws which secure the base to the carb (they point upwards) are commonly found loose.

[Les Kovacs]

Thanks Rob....I will try to locate the 3 upward pointing screws on the carb base and tighten them....I have noticed over the months that many nuts & screws were loose possibly due to the rough ride and overall shacking the jeeps does as I drive it.

I will take off the cap and check everything underneath....however, I will not replace the points & condenser as you suggest. However, I have heard that you have to lube some points pad?....this is mentioned in the manual I have but there is no picture.....any chance that you can send me a pic as to what has to be lubed under the distributor cap?

Regards,

les